1. Field of the Invention
The invention concerns a device for measuring deformations in an elongated machine component, especially the doctor beam of a coater for coating webs of material, paper or cardboard for example.
2. Field of the Invention
Known paper and cardboard coaters have a coating-flow control mechanism in the form of a flexible doctor. The doctor is secured to a beam that extends over the width of the machine. Deformations in the doctor beam lead to irregularities in the cross-section of the coating and to coating results that cannot be reproduced. These deformations occur in the form of sagging for example due to the beam's inherent weight or to changes in temperature.
A coater with a doctor that rests on a batten secured to a pivoting beam is known from German Patent 2 825 907. The batten can be adjusted along the line of contact by tension and compression screws. Geometric errors in the doctor tension or support that lead to changes in the geometry of or pressure applied by the doctor and hence in the weight of the coating can accordingly be compensated for at the beginning of the coating operation. It is, however, impossible to directly measure the deformation of the doctor beam and hence to automatically compensate for errors before or during operation.
The object of the present invention is to provide a device that can constantly measure deformations in an elongated machine component, especially the doctor beam of a coater, during operation.